body {
    width: 100%;
    max-width: 640px;
    min-width: 320px;
    margin: 0 auto;
    background-color: #fff;
    font-size: 14px;
    font-family: -apple-system, 'Helvetica Neue', sans-serif;
    line-height: 1.5;
    color: #666;
}
/* 顶部实现 */

/*点击高亮我们需要清除清除  设置为transparent 完成透明*/

* {
    -webkit-tap-highlight-color: transparent;
}


/*在移动端浏览器默认的外观在iOS上加上这个属性才能给按钮和输入框自定义样式*/

input {
    -webkit-appearance: none;
}


/*禁用长按页面时的弹出菜单*/

img,
a {
    -webkit-touch-callout: none;
}
ul {
    margin: 0;
    padding: 0;
    list-style: none;
}
a {
    color: #666;
    text-decoration: none;
}
.clearfix:after {
    content: "";
    display: block;
    line-height: 0;
    visibility: hidden;
    height: 0;
    clear: both;
}
.app {
    height: 45px;
}
.app ul li {
    float: left;
    height: 45px;
    line-height: 45px;
    background-color: #333;
    text-align: center;
    color: #fff;
}
.app ul li:nth-child(1) {
    width: 8%;
}
.app ul li:nth-child(1) img {
    width: 10px;
}
.app ul li:nth-child(2) {
    width: 10%;
}
.app ul li:nth-child(2) img {
    width: 30px;
    /* 图片是行内块元素，默认和文字基线对齐，改为middle对齐即可 */
    vertical-align: middle;
}
.app ul li:nth-child(3) {
    width: 57%;
}
.app ul li:nth-child(4) {
    width: 25%;
    background-color: rgb(190, 33, 7);
}
/* 搜索模块实现 */
.search-wrap {
    position: fixed;
    /* top: 0px; */
    min-width: 320px;
    max-width: 640px;
    width: 100%;
    height: 44px;
    /* 解决外边距合并问题 */
    overflow: hidden;
}
.search-btn {
    position: absolute;
    top: 0;
    left: 0;
    height: 44px;
    width: 40px;
}
.search-btn::before {
    content: '';
    display: block;
    width: 20px;
    height: 18px;
    background: url(../images/s-btn.png) no-repeat;
    background-size: 20px 18px;
    margin: 14px 0 0 15px;
}
.search {
    position: relative;
    height: 30px;
    margin:0 50px;
    background-color: skyblue;
    border-radius: 15px;
    margin-top: 7px;
}
.jd-icon {
    position: absolute;
    top: 10px;
    left: 10px;
    width: 20px;
    height: 15px;
    background: url(../images/jd.png) no-repeat;
    background-size: 100% 100%;
}
.jd-icon::after {
    position: absolute;
    top: -1px;
    left: 25px;
    content: '';
    width: 1px;
    height: 16px;
    background-color: #fff;
}
.sou {
    position:absolute;
    top: 10px;
    left: 50px;
    width: 18px;
    height: 15px;
    background: url(../images/jd-sprites.png) no-repeat -81px 0px;
    background-size: 200px;
}
.search-login {
    position: absolute;
    top: 0;
    right: 0;
    height: 44px;
    width: 40px;
    color: #fff;
    line-height: 44px
}
/* 解决图片下面有边距的问题 */
img {
    vertical-align: middle;
}
/* 主体内容部分 */
.slider img {
    width: 100%;
}
.brand {
    overflow: hidden;
    border-radius: 10px 10px 0 0 ;
}
.brand div {
    float: left;
    width: 33.33%;
}
.brand div img {
    width: 100%;
}
/* nav部分 */
nav {
    padding-top: 10px;
}
nav a {
    float: left;
    width: 20%;
    text-align: center;
}
nav a img {
    width: 40px;
    margin: 10px 0;
}
nav a span {
    display: block;
}
/* 新闻快报模块 */
.news {
    margin-top: 10px;
}
.news a:nth-child(1) {
    width: 50%;
}
.news a:nth-child(2),
.news a:nth-child(3){
    width: 25%;
    border-left: 1px #ccc solid;
    box-sizing: border-box;
}
.news a {
    float: left;
}
.news a img {
    width: 100%;
}